"To be desired" is a phrase often used to describe something that is lacking or not up to par. However, there are a multitude of synonyms that can convey the same sentiment with slightly different connotations. One such word is "wanting", which implies a clear gap between what is expected and what exists. "Inadequate" suggests a more inherent flaw in something's design or execution. "Unsatisfactory" conveys a sense of disappointment or frustration with the result. "Unfulfilling" may be used to describe something that falls short of one's expectations or does not provide the desired outcome. Ultimately, choosing the right synonym depends on the context and the intended message.